1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
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  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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  20  * or visit www.oracle.com if you need additional information or have any
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  24 
  25 #ifndef SHARE_CODE_NMETHOD_HPP
  26 #define SHARE_CODE_NMETHOD_HPP
  27 
  28 #include "code/codeBlob.hpp"
  29 #include "code/pcDesc.hpp"
  30 #include "oops/metadata.hpp"
  31 #include "oops/method.hpp"
  32 
  33 class AbstractCompiler;
  34 class CompiledDirectCall;
  35 class CompiledIC;
  36 class CompiledICData;
  37 class CompileTask;
  38 class DepChange;
  39 class Dependencies;
  40 class DirectiveSet;
  41 class DebugInformationRecorder;
  42 class ExceptionHandlerTable;
  43 class ImplicitExceptionTable;
  44 class JvmtiThreadState;
  45 class MetadataClosure;
  46 class NativeCallWrapper;
  47 class OopIterateClosure;
  48 class AOTCodeReader;
  49 class AOTCodeEntry;
  50 class ScopeDesc;
  51 class xmlStream;
  52 
  53 // This class is used internally by nmethods, to cache
  54 // exception/pc/handler information.
  55 
  56 class ExceptionCache : public CHeapObj<mtCode> {
  57   friend class VMStructs;
  58  private:
  59   enum { cache_size = 16 };
  60   Klass*   _exception_type;
  61   address  _pc[cache_size];
  62   address  _handler[cache_size];
  63   volatile int _count;
  64   ExceptionCache* volatile _next;
  65   ExceptionCache* _purge_list_next;
  66 
  67   inline address pc_at(int index);
  68   void set_pc_at(int index, address a)      { assert(index >= 0 && index < cache_size,""); _pc[index] = a; }
  69 
  70   inline address handler_at(int index);
  71   void set_handler_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _handler[index] = a; }
  72 
  73   inline int count();
  74   // increment_count is only called under lock, but there may be concurrent readers.
  75   void increment_count();
  76 
  77  public:
  78 
  79   ExceptionCache(Handle exception, address pc, address handler);
  80 
  81   Klass*    exception_type()                { return _exception_type; }
  82   ExceptionCache* next();
  83   void      set_next(ExceptionCache *ec);
  84   ExceptionCache* purge_list_next()                 { return _purge_list_next; }
  85   void      set_purge_list_next(ExceptionCache *ec) { _purge_list_next = ec; }
  86 
  87   address match(Handle exception, address pc);
  88   bool    match_exception_with_space(Handle exception) ;
  89   address test_address(address addr);
  90   bool    add_address_and_handler(address addr, address handler) ;
  91 };
  92 
  93 // cache pc descs found in earlier inquiries
  94 class PcDescCache {
  95   friend class VMStructs;
  96  private:
  97   enum { cache_size = 4 };
  98   // The array elements MUST be volatile! Several threads may modify
  99   // and read from the cache concurrently. find_pc_desc_internal has
 100   // returned wrong results. C++ compiler (namely xlC12) may duplicate
 101   // C++ field accesses if the elements are not volatile.
 102   typedef PcDesc* PcDescPtr;
 103   volatile PcDescPtr _pc_descs[cache_size]; // last cache_size pc_descs found
 104  public:
 105   PcDescCache() { DEBUG_ONLY(_pc_descs[0] = nullptr); }
 106   void    init_to(PcDesc* initial_pc_desc);
 107   PcDesc* find_pc_desc(int pc_offset, bool approximate);
 108   void    add_pc_desc(PcDesc* pc_desc);
 109   PcDesc* last_pc_desc() { return _pc_descs[0]; }
 110 };
 111 
 112 class PcDescContainer : public CHeapObj<mtCode> {
 113 private:
 114   PcDescCache _pc_desc_cache;
 115 public:
 116   PcDescContainer(PcDesc* initial_pc_desc) { _pc_desc_cache.init_to(initial_pc_desc); }
 117 
 118   PcDesc* find_pc_desc_internal(address pc, bool approximate, address code_begin,
 119                                 PcDesc* lower, PcDesc* upper);
 120 
 121   PcDesc* find_pc_desc(address pc, bool approximate, address code_begin, PcDesc* lower, PcDesc* upper)
 122 #ifdef PRODUCT
 123   {
 124     PcDesc* desc = _pc_desc_cache.last_pc_desc();
 125     assert(desc != nullptr, "PcDesc cache should be initialized already");
 126     if (desc->pc_offset() == (pc - code_begin)) {
 127       // Cached value matched
 128       return desc;
 129     }
 130     return find_pc_desc_internal(pc, approximate, code_begin, lower, upper);
 131   }
 132 #endif
 133   ;
 134 };
 135 
 136 // nmethods (native methods) are the compiled code versions of Java methods.
 137 //
 138 // An nmethod contains:
 139 //  - Header                 (the nmethod structure)
 140 //  - Constant part          (doubles, longs and floats used in nmethod)
 141 //  - Code part:
 142 //    - Code body
 143 //    - Exception handler
 144 //    - Stub code
 145 //    - OOP table
 146 //
 147 // As a CodeBlob, an nmethod references [mutable data] allocated on the C heap:
 148 //  - CodeBlob relocation data
 149 //  - Metainfo
 150 //  - JVMCI data
 151 //
 152 // An nmethod references [immutable data] allocated on C heap:
 153 //  - Dependency assertions data
 154 //  - Implicit null table array
 155 //  - Handler entry point array
 156 //  - Debugging information:
 157 //    - Scopes data array
 158 //    - Scopes pcs array
 159 //  - JVMCI speculations array
 160 
 161 #if INCLUDE_JVMCI
 162 class FailedSpeculation;
 163 class JVMCINMethodData;
 164 #endif
 165 
 166 class nmethod : public CodeBlob {
 167   friend class VMStructs;
 168   friend class JVMCIVMStructs;
 169   friend class CodeCache;  // scavengable oops
 170   friend class JVMCINMethodData;
 171   friend class DeoptimizationScope;
 172 
 173  private:
 174 
 175   // Used to track in which deoptimize handshake this method will be deoptimized.
 176   uint64_t  _deoptimization_generation;
 177 
 178   uint64_t  _gc_epoch;
 179 
 180   // Profiling counter used to figure out the hottest nmethods to record into CDS
 181   volatile uint64_t _method_profiling_count;
 182 
 183   Method*   _method;
 184 
 185   // To reduce header size union fields which usages do not overlap.
 186   union {
 187     // To support simple linked-list chaining of nmethods:
 188     nmethod*  _osr_link; // from InstanceKlass::osr_nmethods_head
 189     struct {
 190       // These are used for compiled synchronized native methods to
 191       // locate the owner and stack slot for the BasicLock. They are
 192       // needed because there is no debug information for compiled native
 193       // wrappers and the oop maps are insufficient to allow
 194       // frame::retrieve_receiver() to work. Currently they are expected
 195       // to be byte offsets from the Java stack pointer for maximum code
 196       // sharing between platforms. JVMTI's GetLocalInstance() uses these
 197       // offsets to find the receiver for non-static native wrapper frames.
 198       ByteSize _native_receiver_sp_offset;
 199       ByteSize _native_basic_lock_sp_offset;
 200     };
 201   };
 202 
 203   // nmethod's read-only data
 204   address _immutable_data;
 205 
 206   PcDescContainer* _pc_desc_container;
 207   ExceptionCache* volatile _exception_cache;
 208 
 209   void* _gc_data;
 210 
 211   struct oops_do_mark_link; // Opaque data type.
 212   static nmethod*    volatile _oops_do_mark_nmethods;
 213   oops_do_mark_link* volatile _oops_do_mark_link;
 214 
 215   CompiledICData* _compiled_ic_data;
 216 
 217   // offsets for entry points
 218   address  _osr_entry_point;       // entry point for on stack replacement
 219   uint16_t _entry_offset;          // entry point with class check
 220   uint16_t _verified_entry_offset; // entry point without class check
 221   int      _entry_bci;             // != InvocationEntryBci if this nmethod is an on-stack replacement method
 222   int      _immutable_data_size;
 223 
 224   // _consts_offset == _content_offset because SECT_CONSTS is first in code buffer
 225 
 226   int _skipped_instructions_size;
 227 
 228   int _stub_offset;
 229 
 230   // Offsets for different stubs section parts
 231   int _exception_offset;
 232   // All deoptee's will resume execution at this location described by
 233   // this offset.
 234   int _deopt_handler_offset;
 235   // All deoptee's at a MethodHandle call site will resume execution
 236   // at this location described by this offset.
 237   int _deopt_mh_handler_offset;
 238   // Offset (from insts_end) of the unwind handler if it exists
 239   int16_t  _unwind_handler_offset;
 240   // Number of arguments passed on the stack
 241   uint16_t _num_stack_arg_slots;
 242 
 243   uint16_t _oops_size;
 244 #if INCLUDE_JVMCI
 245   // _metadata_size is not specific to JVMCI. In the non-JVMCI case, it can be derived as:
 246   // _metadata_size = mutable_data_size - relocation_size
 247   uint16_t _metadata_size;
 248 #endif
 249 
 250   // Offset in immutable data section
 251   // _dependencies_offset == 0
 252   uint16_t _nul_chk_table_offset;
 253   uint16_t _handler_table_offset; // This table could be big in C1 code
 254   int      _scopes_pcs_offset;
 255   int      _scopes_data_offset;
 256 #if INCLUDE_JVMCI
 257   int      _speculations_offset;
 258 #endif
 259 
 260   // location in frame (offset for sp) that deopt can store the original
 261   // pc during a deopt.
 262   int _orig_pc_offset;
 263 
 264   int          _compile_id;            // which compilation made this nmethod
 265   CompLevel    _comp_level;            // compilation level (s1)
 266   CompilerType _compiler_type;         // which compiler made this nmethod (u1)
 267 
 268   AOTCodeEntry* _aot_code_entry;
 269 
 270   bool _used; // has this nmethod ever been invoked?
 271 
 272   // Local state used to keep track of whether unloading is happening or not
 273   volatile uint8_t _is_unloading_state;
 274 
 275   // Protected by NMethodState_lock
 276   volatile signed char _state;         // {not_installed, in_use, not_entrant}
 277 
 278   // set during construction
 279   uint8_t _has_unsafe_access:1,        // May fault due to unsafe access.
 280           _has_method_handle_invokes:1,// Has this method MethodHandle invokes?
 281           _has_wide_vectors:1,         // Preserve wide vectors at safepoints
 282           _has_monitors:1,             // Fastpath monitor detection for continuations
 283           _has_scoped_access:1,        // used by for shared scope closure (scopedMemoryAccess.cpp)
 284           _has_flushed_dependencies:1, // Used for maintenance of dependencies (under CodeCache_lock)
 285           _is_unlinked:1,              // mark during class unloading
 286           _load_reported:1,            // used by jvmti to track if an event has been posted for this nmethod
 287           _preloaded:1,
 288           _has_clinit_barriers:1;
 289 
 290   enum DeoptimizationStatus : u1 {
 291     not_marked,
 292     deoptimize,
 293     deoptimize_noupdate,
 294     deoptimize_done
 295   };
 296 
 297   volatile DeoptimizationStatus _deoptimization_status; // Used for stack deoptimization
 298 
 299   DeoptimizationStatus deoptimization_status() const {
 300     return Atomic::load(&_deoptimization_status);
 301   }
 302 
 303   // Initialize fields to their default values
 304   void init_defaults(CodeBuffer *code_buffer, CodeOffsets* offsets);
 305 
 306   // Post initialization
 307   void post_init();
 308 
 309   // For native wrappers
 310   nmethod(Method* method,
 311           CompilerType type,
 312           int nmethod_size,
 313           int compile_id,
 314           CodeOffsets* offsets,
 315           CodeBuffer *code_buffer,
 316           int frame_size,
 317           ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */
 318           ByteSize basic_lock_sp_offset,       /* synchronized natives only */
 319           OopMapSet* oop_maps,
 320           int mutable_data_size);
 321 
 322   // For normal JIT compiled code
 323   nmethod(Method* method,
 324           CompilerType type,
 325           int nmethod_size,
 326           int immutable_data_size,
 327           int mutable_data_size,
 328           int compile_id,
 329           int entry_bci,
 330           address immutable_data,
 331           CodeOffsets* offsets,
 332           int orig_pc_offset,
 333           DebugInformationRecorder *recorder,
 334           Dependencies* dependencies,
 335           CodeBuffer *code_buffer,
 336           int frame_size,
 337           OopMapSet* oop_maps,
 338           ExceptionHandlerTable* handler_table,
 339           ImplicitExceptionTable* nul_chk_table,
 340           AbstractCompiler* compiler,
 341           CompLevel comp_level
 342           , AOTCodeEntry* aot_code_entry
 343 #if INCLUDE_JVMCI
 344           , char* speculations = nullptr,
 345           int speculations_len = 0,
 346           JVMCINMethodData* jvmci_data = nullptr
 347 #endif
 348           );
 349 
 350   // helper methods
 351   void* operator new(size_t size, int nmethod_size, int comp_level) throw();
 352 
 353   // For method handle intrinsics: Try MethodNonProfiled, MethodProfiled and NonNMethod.
 354   // Attention: Only allow NonNMethod space for special nmethods which don't need to be
 355   // findable by nmethod iterators! In particular, they must not contain oops!
 356   void* operator new(size_t size, int nmethod_size, bool allow_NonNMethod_space) throw();
 357 
 358   const char* reloc_string_for(u_char* begin, u_char* end);
 359 
 360   bool try_transition(signed char new_state);
 361 
 362   // Returns true if this thread changed the state of the nmethod or
 363   // false if another thread performed the transition.
 364   bool make_entrant() { Unimplemented(); return false; }
 365   void inc_decompile_count();
 366 
 367   // Inform external interfaces that a compiled method has been unloaded
 368   void post_compiled_method_unload();
 369 
 370   PcDesc* find_pc_desc(address pc, bool approximate) {
 371     if (_pc_desc_container == nullptr) return nullptr; // native method
 372     return _pc_desc_container->find_pc_desc(pc, approximate, code_begin(), scopes_pcs_begin(), scopes_pcs_end());
 373   }
 374 
 375   // STW two-phase nmethod root processing helpers.
 376   //
 377   // When determining liveness of a given nmethod to do code cache unloading,
 378   // some collectors need to do different things depending on whether the nmethods
 379   // need to absolutely be kept alive during root processing; "strong"ly reachable
 380   // nmethods are known to be kept alive at root processing, but the liveness of
 381   // "weak"ly reachable ones is to be determined later.
 382   //
 383   // We want to allow strong and weak processing of nmethods by different threads
 384   // at the same time without heavy synchronization. Additional constraints are
 385   // to make sure that every nmethod is processed a minimal amount of time, and
 386   // nmethods themselves are always iterated at most once at a particular time.
 387   //
 388   // Note that strong processing work must be a superset of weak processing work
 389   // for this code to work.
 390   //
 391   // We store state and claim information in the _oops_do_mark_link member, using
 392   // the two LSBs for the state and the remaining upper bits for linking together
 393   // nmethods that were already visited.
 394   // The last element is self-looped, i.e. points to itself to avoid some special
 395   // "end-of-list" sentinel value.
 396   //
 397   // _oops_do_mark_link special values:
 398   //
 399   //   _oops_do_mark_link == nullptr: the nmethod has not been visited at all yet, i.e.
 400   //      is Unclaimed.
 401   //
 402   // For other values, its lowest two bits indicate the following states of the nmethod:
 403   //
 404   //   weak_request (WR): the nmethod has been claimed by a thread for weak processing
 405   //   weak_done (WD): weak processing has been completed for this nmethod.
 406   //   strong_request (SR): the nmethod has been found to need strong processing while
 407   //       being weak processed.
 408   //   strong_done (SD): strong processing has been completed for this nmethod .
 409   //
 410   // The following shows the _only_ possible progressions of the _oops_do_mark_link
 411   // pointer.
 412   //
 413   // Given
 414   //   N as the nmethod
 415   //   X the current next value of _oops_do_mark_link
 416   //
 417   // Unclaimed (C)-> N|WR (C)-> X|WD: the nmethod has been processed weakly by
 418   //   a single thread.
 419   // Unclaimed (C)-> N|WR (C)-> X|WD (O)-> X|SD: after weak processing has been
 420   //   completed (as above) another thread found that the nmethod needs strong
 421   //   processing after all.
 422   // Unclaimed (C)-> N|WR (O)-> N|SR (C)-> X|SD: during weak processing another
 423   //   thread finds that the nmethod needs strong processing, marks it as such and
 424   //   terminates. The original thread completes strong processing.
 425   // Unclaimed (C)-> N|SD (C)-> X|SD: the nmethod has been processed strongly from
 426   //   the beginning by a single thread.
 427   //
 428   // "|" describes the concatenation of bits in _oops_do_mark_link.
 429   //
 430   // The diagram also describes the threads responsible for changing the nmethod to
 431   // the next state by marking the _transition_ with (C) and (O), which mean "current"
 432   // and "other" thread respectively.
 433   //
 434 
 435   // States used for claiming nmethods during root processing.
 436   static const uint claim_weak_request_tag = 0;
 437   static const uint claim_weak_done_tag = 1;
 438   static const uint claim_strong_request_tag = 2;
 439   static const uint claim_strong_done_tag = 3;
 440 
 441   static oops_do_mark_link* mark_link(nmethod* nm, uint tag) {
 442     assert(tag <= claim_strong_done_tag, "invalid tag %u", tag);
 443     assert(is_aligned(nm, 4), "nmethod pointer must have zero lower two LSB");
 444     return (oops_do_mark_link*)(((uintptr_t)nm & ~0x3) | tag);
 445   }
 446 
 447   static uint extract_state(oops_do_mark_link* link) {
 448     return (uint)((uintptr_t)link & 0x3);
 449   }
 450 
 451   static nmethod* extract_nmethod(oops_do_mark_link* link) {
 452     return (nmethod*)((uintptr_t)link & ~0x3);
 453   }
 454 
 455   void oops_do_log_change(const char* state);
 456 
 457   static bool oops_do_has_weak_request(oops_do_mark_link* next) {
 458     return extract_state(next) == claim_weak_request_tag;
 459   }
 460 
 461   static bool oops_do_has_any_strong_state(oops_do_mark_link* next) {
 462     return extract_state(next) >= claim_strong_request_tag;
 463   }
 464 
 465   // Attempt Unclaimed -> N|WR transition. Returns true if successful.
 466   bool oops_do_try_claim_weak_request();
 467 
 468   // Attempt Unclaimed -> N|SD transition. Returns the current link.
 469   oops_do_mark_link* oops_do_try_claim_strong_done();
 470   // Attempt N|WR -> X|WD transition. Returns nullptr if successful, X otherwise.
 471   nmethod* oops_do_try_add_to_list_as_weak_done();
 472 
 473   // Attempt X|WD -> N|SR transition. Returns the current link.
 474   oops_do_mark_link* oops_do_try_add_strong_request(oops_do_mark_link* next);
 475   // Attempt X|WD -> X|SD transition. Returns true if successful.
 476   bool oops_do_try_claim_weak_done_as_strong_done(oops_do_mark_link* next);
 477 
 478   // Do the N|SD -> X|SD transition.
 479   void oops_do_add_to_list_as_strong_done();
 480 
 481   // Sets this nmethod as strongly claimed (as part of N|SD -> X|SD and N|SR -> X|SD
 482   // transitions).
 483   void oops_do_set_strong_done(nmethod* old_head);
 484 
 485   void record_nmethod_dependency();
 486 
 487   void restore_from_archive(nmethod* archived_nm,
 488                             const methodHandle& method,
 489                             int compile_id,
 490                             address reloc_data,
 491                             GrowableArray<Handle>& oop_list,
 492                             GrowableArray<Metadata*>& metadata_list,
 493                             ImmutableOopMapSet* oop_maps,
 494                             address immutable_data,
 495                             GrowableArray<Handle>& reloc_imm_oop_list,
 496                             GrowableArray<Metadata*>& reloc_imm_metadata_list,
 497 #ifndef PRODUCT
 498                             AsmRemarks& asm_remarks,
 499                             DbgStrings& dbg_strings,
 500 #endif /* PRODUCT */
 501                             AOTCodeReader* aot_code_reader);
 502 
 503 public:
 504   // create nmethod using archived nmethod from AOT code cache
 505   static nmethod* new_nmethod(nmethod* archived_nm,
 506                               const methodHandle& method,
 507                               AbstractCompiler* compiler,
 508                               int compile_id,
 509                               address reloc_data,
 510                               GrowableArray<Handle>& oop_list,
 511                               GrowableArray<Metadata*>& metadata_list,
 512                               ImmutableOopMapSet* oop_maps,
 513                               address immutable_data,
 514                               GrowableArray<Handle>& reloc_imm_oop_list,
 515                               GrowableArray<Metadata*>& reloc_imm_metadata_list,
 516 #ifndef PRODUCT
 517                               AsmRemarks& asm_remarks,
 518                               DbgStrings& dbg_strings,
 519 #endif /* PRODUCT */
 520                               AOTCodeReader* aot_code_reader);
 521 
 522   // create nmethod with entry_bci
 523   static nmethod* new_nmethod(const methodHandle& method,
 524                               int compile_id,
 525                               int entry_bci,
 526                               CodeOffsets* offsets,
 527                               int orig_pc_offset,
 528                               DebugInformationRecorder* recorder,
 529                               Dependencies* dependencies,
 530                               CodeBuffer *code_buffer,
 531                               int frame_size,
 532                               OopMapSet* oop_maps,
 533                               ExceptionHandlerTable* handler_table,
 534                               ImplicitExceptionTable* nul_chk_table,
 535                               AbstractCompiler* compiler,
 536                               CompLevel comp_level
 537                               , AOTCodeEntry* aot_code_entry
 538 #if INCLUDE_JVMCI
 539                               , char* speculations = nullptr,
 540                               int speculations_len = 0,
 541                               JVMCINMethodData* jvmci_data = nullptr
 542 #endif
 543   );
 544 
 545   static nmethod* new_native_nmethod(const methodHandle& method,
 546                                      int compile_id,
 547                                      CodeBuffer *code_buffer,
 548                                      int vep_offset,
 549                                      int frame_complete,
 550                                      int frame_size,
 551                                      ByteSize receiver_sp_offset,
 552                                      ByteSize basic_lock_sp_offset,
 553                                      OopMapSet* oop_maps,
 554                                      int exception_handler = -1);
 555 
 556   Method* method       () const { return _method; }
 557   uint16_t entry_bci   () const { return _entry_bci; }
 558   bool is_native_method() const { return _method != nullptr && _method->is_native(); }
 559   bool is_java_method  () const { return _method != nullptr && !_method->is_native(); }
 560   bool is_osr_method   () const { return _entry_bci != InvocationEntryBci; }
 561 
 562   // Compiler task identification.  Note that all OSR methods
 563   // are numbered in an independent sequence if CICountOSR is true,
 564   // and native method wrappers are also numbered independently if
 565   // CICountNative is true.
 566   int compile_id() const { return _compile_id; }
 567   const char* compile_kind() const;
 568 
 569   inline bool  is_compiled_by_c1   () const { return _compiler_type == compiler_c1; }
 570   inline bool  is_compiled_by_c2   () const { return _compiler_type == compiler_c2; }
 571   inline bool  is_compiled_by_jvmci() const { return _compiler_type == compiler_jvmci; }
 572   CompilerType compiler_type       () const { return _compiler_type; }
 573   const char*  compiler_name       () const;
 574 
 575   // boundaries for different parts
 576   address consts_begin          () const { return           content_begin(); }
 577   address consts_end            () const { return           code_begin()   ; }
 578   address insts_begin           () const { return           code_begin()   ; }
 579   address insts_end             () const { return           header_begin() + _stub_offset             ; }
 580   address stub_begin            () const { return           header_begin() + _stub_offset             ; }
 581   address stub_end              () const { return           code_end()     ; }
 582   address exception_begin       () const { return           header_begin() + _exception_offset        ; }
 583   address deopt_handler_begin   () const { return           header_begin() + _deopt_handler_offset    ; }
 584   address deopt_mh_handler_begin() const { return _deopt_mh_handler_offset != -1 ? (header_begin() + _deopt_mh_handler_offset) : nullptr; }
 585   address unwind_handler_begin  () const { return _unwind_handler_offset != -1 ? (insts_end() - _unwind_handler_offset) : nullptr; }
 586   oop*    oops_begin            () const { return (oop*)    data_begin(); }
 587   oop*    oops_end              () const { return (oop*)    data_end(); }
 588 
 589   // mutable data
 590   Metadata** metadata_begin     () const { return (Metadata**) (mutable_data_begin() + _relocation_size); }
 591 #if INCLUDE_JVMCI
 592   Metadata** metadata_end       () const { return (Metadata**) (mutable_data_begin() + _relocation_size + _metadata_size); }
 593   address jvmci_data_begin      () const { return               mutable_data_begin() + _relocation_size + _metadata_size; }
 594   address jvmci_data_end        () const { return               mutable_data_end(); }
 595 #else
 596   Metadata** metadata_end       () const { return (Metadata**)  mutable_data_end(); }
 597 #endif
 598 
 599   // immutable data
 600   void set_immutable_data(address data) { _immutable_data = data; }
 601   address immutable_data_begin  () const { return           _immutable_data; }
 602   address immutable_data_end    () const { return           _immutable_data + _immutable_data_size ; }
 603   address dependencies_begin    () const { return           _immutable_data; }
 604   address dependencies_end      () const { return           _immutable_data + _nul_chk_table_offset; }
 605   address nul_chk_table_begin   () const { return           _immutable_data + _nul_chk_table_offset; }
 606   address nul_chk_table_end     () const { return           _immutable_data + _handler_table_offset; }
 607   address handler_table_begin   () const { return           _immutable_data + _handler_table_offset; }
 608   address handler_table_end     () const { return           _immutable_data + _scopes_pcs_offset   ; }
 609   PcDesc* scopes_pcs_begin      () const { return (PcDesc*)(_immutable_data + _scopes_pcs_offset)  ; }
 610   PcDesc* scopes_pcs_end        () const { return (PcDesc*)(_immutable_data + _scopes_data_offset) ; }
 611   address scopes_data_begin     () const { return           _immutable_data + _scopes_data_offset  ; }
 612 
 613 #if INCLUDE_JVMCI
 614   address scopes_data_end       () const { return           _immutable_data + _speculations_offset ; }
 615   address speculations_begin    () const { return           _immutable_data + _speculations_offset ; }
 616   address speculations_end      () const { return            immutable_data_end(); }
 617 #else
 618   address scopes_data_end       () const { return            immutable_data_end(); }
 619 #endif
 620 
 621   // Sizes
 622   int immutable_data_size() const { return _immutable_data_size; }
 623   int consts_size        () const { return int(          consts_end       () -           consts_begin       ()); }
 624   int insts_size         () const { return int(          insts_end        () -           insts_begin        ()); }
 625   int stub_size          () const { return int(          stub_end         () -           stub_begin         ()); }
 626   int oops_size          () const { return int((address) oops_end         () - (address) oops_begin         ()); }
 627   int metadata_size      () const { return int((address) metadata_end     () - (address) metadata_begin     ()); }
 628   int scopes_data_size   () const { return int(          scopes_data_end  () -           scopes_data_begin  ()); }
 629   int scopes_pcs_size    () const { return int((intptr_t)scopes_pcs_end   () - (intptr_t)scopes_pcs_begin   ()); }
 630   int dependencies_size  () const { return int(          dependencies_end () -           dependencies_begin ()); }
 631   int handler_table_size () const { return int(          handler_table_end() -           handler_table_begin()); }
 632   int nul_chk_table_size () const { return int(          nul_chk_table_end() -           nul_chk_table_begin()); }
 633 #if INCLUDE_JVMCI
 634   int speculations_size  () const { return int(          speculations_end () -           speculations_begin ()); }
 635   int jvmci_data_size    () const { return int(          jvmci_data_end   () -           jvmci_data_begin   ()); }
 636 #endif
 637 
 638   int     oops_count() const { assert(oops_size() % oopSize == 0, "");  return (oops_size() / oopSize) + 1; }
 639   int metadata_count() const { assert(metadata_size() % wordSize == 0, ""); return (metadata_size() / wordSize) + 1; }
 640 
 641   int skipped_instructions_size () const { return _skipped_instructions_size; }
 642   int total_size() const;
 643 
 644   // Containment
 645   bool consts_contains         (address addr) const { return consts_begin       () <= addr && addr < consts_end       (); }
 646   // Returns true if a given address is in the 'insts' section. The method
 647   // insts_contains_inclusive() is end-inclusive.
 648   bool insts_contains          (address addr) const { return insts_begin        () <= addr && addr < insts_end        (); }
 649   bool insts_contains_inclusive(address addr) const { return insts_begin        () <= addr && addr <= insts_end       (); }
 650   bool stub_contains           (address addr) const { return stub_begin         () <= addr && addr < stub_end         (); }
 651   bool oops_contains           (oop*    addr) const { return oops_begin         () <= addr && addr < oops_end         (); }
 652   bool metadata_contains       (Metadata** addr) const { return metadata_begin  () <= addr && addr < metadata_end     (); }
 653   bool scopes_data_contains    (address addr) const { return scopes_data_begin  () <= addr && addr < scopes_data_end  (); }
 654   bool scopes_pcs_contains     (PcDesc* addr) const { return scopes_pcs_begin   () <= addr && addr < scopes_pcs_end   (); }
 655   bool handler_table_contains  (address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); }
 656   bool nul_chk_table_contains  (address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); }
 657 
 658   // entry points
 659   address entry_point() const          { return code_begin() + _entry_offset;          } // normal entry point
 660   address verified_entry_point() const { return code_begin() + _verified_entry_offset; } // if klass is correct
 661 
 662   enum : signed char { not_installed = -1, // in construction, only the owner doing the construction is
 663                                            // allowed to advance state
 664                        in_use        = 0,  // executable nmethod
 665                        not_entrant   = 1   // marked for deoptimization but activations may still exist
 666   };
 667 
 668   // flag accessing and manipulation
 669   bool is_not_installed() const        { return _state == not_installed; }
 670   bool is_in_use() const               { return _state <= in_use; }
 671   bool is_not_entrant() const          { return _state == not_entrant; }
 672   int  get_state() const               { return _state; }
 673 
 674   void clear_unloading_state();
 675   // Heuristically deduce an nmethod isn't worth keeping around
 676   bool is_cold();
 677   bool is_unloading();
 678   void do_unloading(bool unloading_occurred);
 679 
 680   void inc_method_profiling_count();
 681   uint64_t method_profiling_count();
 682 
 683   bool make_in_use() {
 684     return try_transition(in_use);
 685   }
 686   // Make the nmethod non entrant. The nmethod will continue to be
 687   // alive.  It is used when an uncommon trap happens.  Returns true
 688   // if this thread changed the state of the nmethod or false if
 689   // another thread performed the transition.
 690   bool  make_not_entrant(const char* reason, bool make_not_entrant = true);
 691   bool  make_not_used()    { return make_not_entrant("not used"); }
 692 
 693   bool  is_marked_for_deoptimization() const { return deoptimization_status() != not_marked; }
 694   bool  has_been_deoptimized() const { return deoptimization_status() == deoptimize_done; }
 695   void  set_deoptimized_done();
 696 
 697   bool update_recompile_counts() const {
 698     // Update recompile counts when either the update is explicitly requested (deoptimize)
 699     // or the nmethod is not marked for deoptimization at all (not_marked).
 700     // The latter happens during uncommon traps when deoptimized nmethod is made not entrant.
 701     DeoptimizationStatus status = deoptimization_status();
 702     return status != deoptimize_noupdate && status != deoptimize_done;
 703   }
 704 
 705   // tells whether frames described by this nmethod can be deoptimized
 706   // note: native wrappers cannot be deoptimized.
 707   bool can_be_deoptimized() const { return is_java_method(); }
 708 
 709   bool has_dependencies()                         { return dependencies_size() != 0; }
 710   void print_dependencies_on(outputStream* out) PRODUCT_RETURN;
 711   void flush_dependencies();
 712 
 713   template<typename T>
 714   T* gc_data() const                              { return reinterpret_cast<T*>(_gc_data); }
 715   template<typename T>
 716   void set_gc_data(T* gc_data)                    { _gc_data = reinterpret_cast<void*>(gc_data); }
 717 
 718   bool  has_unsafe_access() const                 { return _has_unsafe_access; }
 719   void  set_has_unsafe_access(bool z)             { _has_unsafe_access = z; }
 720 
 721   bool  has_monitors() const                      { return _has_monitors; }
 722   void  set_has_monitors(bool z)                  { _has_monitors = z; }
 723 
 724   bool  has_scoped_access() const                 { return _has_scoped_access; }
 725   void  set_has_scoped_access(bool z)             { _has_scoped_access = z; }
 726 
 727   bool  has_method_handle_invokes() const         { return _has_method_handle_invokes; }
 728   void  set_has_method_handle_invokes(bool z)     { _has_method_handle_invokes = z; }
 729 
 730   bool  has_wide_vectors() const                  { return _has_wide_vectors; }
 731   void  set_has_wide_vectors(bool z)              { _has_wide_vectors = z; }
 732 
 733   bool  has_clinit_barriers() const               { return _has_clinit_barriers; }
 734   void  set_has_clinit_barriers(bool z)           { _has_clinit_barriers = z; }
 735 
 736   bool  preloaded() const                         { return _preloaded; }
 737   void  set_preloaded(bool z)                     { _preloaded = z; }
 738 
 739   bool  has_flushed_dependencies() const          { return _has_flushed_dependencies; }
 740   void  set_has_flushed_dependencies(bool z)      {
 741     assert(!has_flushed_dependencies(), "should only happen once");
 742     _has_flushed_dependencies = z;
 743   }
 744 
 745   bool  is_unlinked() const                       { return _is_unlinked; }
 746   void  set_is_unlinked()                         {
 747      assert(!_is_unlinked, "already unlinked");
 748       _is_unlinked = true;
 749   }
 750 
 751   int   comp_level() const                        { return _comp_level; }
 752 
 753   // Support for oops in scopes and relocs:
 754   // Note: index 0 is reserved for null.
 755   oop   oop_at(int index) const;
 756   oop   oop_at_phantom(int index) const; // phantom reference
 757   oop*  oop_addr_at(int index) const {  // for GC
 758     // relocation indexes are biased by 1 (because 0 is reserved)
 759     assert(index > 0 && index <= oops_count(), "must be a valid non-zero index");
 760     return &oops_begin()[index - 1];
 761   }
 762 
 763   // Support for meta data in scopes and relocs:
 764   // Note: index 0 is reserved for null.
 765   Metadata*   metadata_at(int index) const      { return index == 0 ? nullptr: *metadata_addr_at(index); }
 766   Metadata**  metadata_addr_at(int index) const {  // for GC
 767     // relocation indexes are biased by 1 (because 0 is reserved)
 768     assert(index > 0 && index <= metadata_count(), "must be a valid non-zero index");
 769     return &metadata_begin()[index - 1];
 770   }
 771 
 772   void copy_values(GrowableArray<Handle>* array);
 773   void copy_values(GrowableArray<jobject>* oops);
 774   void copy_values(GrowableArray<Metadata*>* metadata);
 775   void copy_values(GrowableArray<address>* metadata) {} // Nothing to do
 776 
 777   // Relocation support
 778 private:
 779   void fix_oop_relocations(address begin, address end, bool initialize_immediates);
 780   inline void initialize_immediate_oop(oop* dest, jobject handle);
 781 
 782 protected:
 783   address oops_reloc_begin() const;
 784 
 785 public:
 786   void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); }
 787   void fix_oop_relocations()                           { fix_oop_relocations(nullptr, nullptr, false); }
 788 
 789   void create_reloc_immediates_list(JavaThread* thread, GrowableArray<Handle>& oop_list, GrowableArray<Metadata*>& metadata_list);
 790 
 791   bool is_at_poll_return(address pc);
 792   bool is_at_poll_or_poll_return(address pc);
 793 
 794 protected:
 795   // Exception cache support
 796   // Note: _exception_cache may be read and cleaned concurrently.
 797   ExceptionCache* exception_cache() const         { return _exception_cache; }
 798   ExceptionCache* exception_cache_acquire() const;
 799 
 800 public:
 801   address handler_for_exception_and_pc(Handle exception, address pc);
 802   void add_handler_for_exception_and_pc(Handle exception, address pc, address handler);
 803   void clean_exception_cache();
 804 
 805   void add_exception_cache_entry(ExceptionCache* new_entry);
 806   ExceptionCache* exception_cache_entry_for_exception(Handle exception);
 807 
 808 
 809   // MethodHandle
 810   bool is_method_handle_return(address return_pc);
 811   // Deopt
 812   // Return true is the PC is one would expect if the frame is being deopted.
 813   inline bool is_deopt_pc(address pc);
 814   inline bool is_deopt_mh_entry(address pc);
 815   inline bool is_deopt_entry(address pc);
 816 
 817   // Accessor/mutator for the original pc of a frame before a frame was deopted.
 818   address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
 819   void    set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
 820 
 821   const char* state() const;
 822 
 823   bool inlinecache_check_contains(address addr) const {
 824     return (addr >= code_begin() && addr < verified_entry_point());
 825   }
 826 
 827   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f);
 828 
 829   // implicit exceptions support
 830   address continuation_for_implicit_div0_exception(address pc) { return continuation_for_implicit_exception(pc, true); }
 831   address continuation_for_implicit_null_exception(address pc) { return continuation_for_implicit_exception(pc, false); }
 832 
 833   // Inline cache support for class unloading and nmethod unloading
 834  private:
 835   void cleanup_inline_caches_impl(bool unloading_occurred, bool clean_all);
 836 
 837   address continuation_for_implicit_exception(address pc, bool for_div0_check);
 838 
 839  public:
 840   // Serial version used by whitebox test
 841   void cleanup_inline_caches_whitebox();
 842 
 843   void clear_inline_caches();
 844 
 845   // Execute nmethod barrier code, as if entering through nmethod call.
 846   void run_nmethod_entry_barrier();
 847 
 848   void verify_oop_relocations();
 849 
 850   bool has_evol_metadata();
 851 
 852   Method* attached_method(address call_pc);
 853   Method* attached_method_before_pc(address pc);
 854 
 855   // GC unloading support
 856   // Cleans unloaded klasses and unloaded nmethods in inline caches
 857 
 858   void unload_nmethod_caches(bool class_unloading_occurred);
 859 
 860   void unlink_from_method();
 861 
 862   // On-stack replacement support
 863   int      osr_entry_bci()    const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
 864   address  osr_entry()        const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
 865   nmethod* osr_link()         const { return _osr_link; }
 866   void     set_osr_link(nmethod *n) { _osr_link = n; }
 867   void     invalidate_osr_method();
 868 
 869   int num_stack_arg_slots(bool rounded = true) const {
 870     return rounded ? align_up(_num_stack_arg_slots, 2) : _num_stack_arg_slots;
 871   }
 872 
 873   // Verify calls to dead methods have been cleaned.
 874   void verify_clean_inline_caches();
 875 
 876   // Unlink this nmethod from the system
 877   void unlink();
 878 
 879   // Deallocate this nmethod - called by the GC
 880   void purge(bool unregister_nmethod);
 881 
 882   // See comment at definition of _last_seen_on_stack
 883   void mark_as_maybe_on_stack();
 884   bool is_maybe_on_stack();
 885 
 886   // Evolution support. We make old (discarded) compiled methods point to new Method*s.
 887   void set_method(Method* method) { _method = method; }
 888 
 889 #if INCLUDE_JVMCI
 890   // Gets the JVMCI name of this nmethod.
 891   const char* jvmci_name();
 892 
 893   // Records the pending failed speculation in the
 894   // JVMCI speculation log associated with this nmethod.
 895   void update_speculation(JavaThread* thread);
 896 
 897   // Gets the data specific to a JVMCI compiled method.
 898   // This returns a non-nullptr value iff this nmethod was
 899   // compiled by the JVMCI compiler.
 900   JVMCINMethodData* jvmci_nmethod_data() const {
 901     return jvmci_data_size() == 0 ? nullptr : (JVMCINMethodData*) jvmci_data_begin();
 902   }
 903 #endif
 904 
 905   void oops_do(OopClosure* f) { oops_do(f, false); }
 906   void oops_do(OopClosure* f, bool allow_dead);
 907 
 908   // All-in-one claiming of nmethods: returns true if the caller successfully claimed that
 909   // nmethod.
 910   bool oops_do_try_claim();
 911 
 912   // Loom support for following nmethods on the stack
 913   void follow_nmethod(OopIterateClosure* cl);
 914 
 915   // Class containing callbacks for the oops_do_process_weak/strong() methods
 916   // below.
 917   class OopsDoProcessor {
 918   public:
 919     // Process the oops of the given nmethod based on whether it has been called
 920     // in a weak or strong processing context, i.e. apply either weak or strong
 921     // work on it.
 922     virtual void do_regular_processing(nmethod* nm) = 0;
 923     // Assuming that the oops of the given nmethod has already been its weak
 924     // processing applied, apply the remaining strong processing part.
 925     virtual void do_remaining_strong_processing(nmethod* nm) = 0;
 926   };
 927 
 928   // The following two methods do the work corresponding to weak/strong nmethod
 929   // processing.
 930   void oops_do_process_weak(OopsDoProcessor* p);
 931   void oops_do_process_strong(OopsDoProcessor* p);
 932 
 933   static void oops_do_marking_prologue();
 934   static void oops_do_marking_epilogue();
 935 
 936  private:
 937   ScopeDesc* scope_desc_in(address begin, address end);
 938 
 939   address* orig_pc_addr(const frame* fr);
 940 
 941   // used by jvmti to track if the load events has been reported
 942   bool  load_reported() const                     { return _load_reported; }
 943   void  set_load_reported()                       { _load_reported = true; }
 944 
 945  public:
 946   // ScopeDesc retrieval operation
 947   PcDesc* pc_desc_at(address pc)   { return find_pc_desc(pc, false); }
 948   // pc_desc_near returns the first PcDesc at or after the given pc.
 949   PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); }
 950 
 951   // ScopeDesc for an instruction
 952   ScopeDesc* scope_desc_at(address pc);
 953   ScopeDesc* scope_desc_near(address pc);
 954 
 955   // copying of debugging information
 956   void copy_scopes_pcs(PcDesc* pcs, int count);
 957   void copy_scopes_data(address buffer, int size);
 958 
 959   int orig_pc_offset() { return _orig_pc_offset; }
 960 
 961   AOTCodeEntry* aot_code_entry() const { return _aot_code_entry; }
 962   bool is_aot() const { return aot_code_entry() != nullptr; }
 963   void set_aot_code_entry(AOTCodeEntry* entry) { _aot_code_entry = entry; }
 964 
 965   bool     used() const { return _used; }
 966   void set_used()       { _used = true; }
 967 
 968   // Post successful compilation
 969   void post_compiled_method(CompileTask* task);
 970 
 971   // jvmti support:
 972   void post_compiled_method_load_event(JvmtiThreadState* state = nullptr);
 973 
 974   // verify operations
 975   void verify();
 976   void verify_scopes();
 977   void verify_interrupt_point(address interrupt_point, bool is_inline_cache);
 978 
 979   // Disassemble this nmethod with additional debug information, e.g. information about blocks.
 980   void decode2(outputStream* st) const;
 981   void print_constant_pool(outputStream* st);
 982 
 983   // Avoid hiding of parent's 'decode(outputStream*)' method.
 984   void decode(outputStream* st) const { decode2(st); } // just delegate here.
 985 
 986   // printing support
 987   void print_on_impl(outputStream* st) const;
 988   void print_code();
 989   void print_value_on_impl(outputStream* st) const;
 990 
 991 #if defined(SUPPORT_DATA_STRUCTS)
 992   // print output in opt build for disassembler library
 993   void print_relocations_on(outputStream* st)     PRODUCT_RETURN;
 994   void print_pcs_on(outputStream* st);
 995   void print_scopes() { print_scopes_on(tty); }
 996   void print_scopes_on(outputStream* st)          PRODUCT_RETURN;
 997   void print_handler_table();
 998   void print_nul_chk_table();
 999   void print_recorded_oop(int log_n, int index);
1000   void print_recorded_oops();
1001   void print_recorded_metadata();
1002 
1003   void print_oops(outputStream* st);     // oops from the underlying CodeBlob.
1004   void print_metadata(outputStream* st); // metadata in metadata pool.
1005 #else
1006   void print_pcs_on(outputStream* st) { return; }
1007 #endif
1008 
1009   void print_calls(outputStream* st)              PRODUCT_RETURN;
1010   static void print_statistics()                  PRODUCT_RETURN;
1011 
1012   void maybe_print_nmethod(const DirectiveSet* directive);
1013   void print_nmethod(bool print_code);
1014 
1015   void print_on_with_msg(outputStream* st, const char* msg) const;
1016 
1017   // Logging
1018   void log_identity(xmlStream* log) const;
1019   void log_new_nmethod() const;
1020   void log_state_change(const char* reason) const;
1021 
1022   // Prints block-level comments, including nmethod specific block labels:
1023   void print_nmethod_labels(outputStream* stream, address block_begin, bool print_section_labels=true) const;
1024   const char* nmethod_section_label(address pos) const;
1025 
1026   // returns whether this nmethod has code comments.
1027   bool has_code_comment(address begin, address end);
1028   // Prints a comment for one native instruction (reloc info, pc desc)
1029   void print_code_comment_on(outputStream* st, int column, address begin, address end);
1030 
1031   // tells if this compiled method is dependent on the given changes,
1032   // and the changes have invalidated it
1033   bool check_dependency_on(DepChange& changes);
1034 
1035   // Fast breakpoint support. Tells if this compiled method is
1036   // dependent on the given method. Returns true if this nmethod
1037   // corresponds to the given method as well.
1038   bool is_dependent_on_method(Method* dependee);
1039 
1040   // JVMTI's GetLocalInstance() support
1041   ByteSize native_receiver_sp_offset() {
1042     assert(is_native_method(), "sanity");
1043     return _native_receiver_sp_offset;
1044   }
1045   ByteSize native_basic_lock_sp_offset() {
1046     assert(is_native_method(), "sanity");
1047     return _native_basic_lock_sp_offset;
1048   }
1049 
1050   // support for code generation
1051   static ByteSize osr_entry_point_offset() { return byte_offset_of(nmethod, _osr_entry_point); }
1052   static ByteSize state_offset()           { return byte_offset_of(nmethod, _state); }
1053 
1054   void metadata_do(MetadataClosure* f);
1055 
1056   address call_instruction_address(address pc) const;
1057 
1058   void make_deoptimized();
1059   void finalize_relocations();
1060 
1061   void prepare_for_archiving();
1062 
1063   class Vptr : public CodeBlob::Vptr {
1064     void print_on(const CodeBlob* instance, outputStream* st) const override {
1065       ttyLocker ttyl;
1066       instance->as_nmethod()->print_on_impl(st);
1067     }
1068     void print_value_on(const CodeBlob* instance, outputStream* st) const override {
1069       instance->as_nmethod()->print_value_on_impl(st);
1070     }
1071   };
1072 
1073   static const Vptr _vpntr;
1074 };
1075 
1076 #endif // SHARE_CODE_NMETHOD_HPP